Add support of IBM Z cloud OCP to infra of CRW testing pipelines

We need to add support of IBM Z to CRW testing pipelines.

An idea is to add IBM Z to ocpInfra parameter with OCP 4.6/4.7 version https://gitlab.cee.redhat.com/codeready-workspaces/crw-jenkins/-/blob/master/src/com/redhat/codeready/cci/openshift/OpenshiftDto.groovy#L37-83
 

choiceParam("ocpInfra", ['PSI OpenStack', 'AWS', 'RHPDS'])

> 

choiceParam("ocpInfra", ['PSI OpenStack', 'AWS', 'RHPDS', 'IBM Z'])

OCP instances are needed to have:
1) pre-installed admin/user with httpaswd identity provider;
2) configured mirror from registry.redhat.io to brew.registry.redhat.io (require admin (https://main-jenkins-csb-crwqe.apps.ocp4.prod.psi.redhat.com/job/Flexy/job/configure-brew-registry-on-ocp-4x/).

Code snippet to add into https://gitlab.cee.redhat.com/codeready-workspaces/crw-jenkins/-/blob/master/src/com/redhat/codeready/cci/openshift/OpenshiftDto.groovy#L38 :
TODO